Table 3.
HRs for overweight incidence according to sleep duration group among Chinese normal weight children in 6–9 months follow-up
| Group | No. of Participants | No. of new overweight | Model 1a | Model 2b |
|---|---|---|---|---|
| Male | ||||
| > 9 h | 1735 | 47 | 1 | 1 |
| 7–9 h | 3950 | 112 | 1.09(0.77–1.54) | 1.03(0.67–1.59) |
| < 7 h | 855 | 38 | 1.38(0.87–2.21) | 1.21(0.65–2.24) |
| Female | ||||
| > 9 h | 1888 | 46 | 1 | 1 |
| 7–9 h | 4563 | 140 | 1.23(0.87–1.74) | 1.60(1.02–2.52)* |
| < 7 h | 1667 | 50 | 1.28(0.81–2.00) | 1.71(0.95–3.08) |
| Stratified by age and gender | ||||
| Before adolescents | ||||
| Male (6–11 years) | ||||
| > 9 h | 1416 | 43 | 1 | 1 |
| 7–9 h | 2148 | 66 | 1.04(0.71–1.53) | 1.05(0.65–1.70) |
| < 7 h | 302 | 7 | 0.84(0.38–1.86) | 0.84(0.29–2.40) |
| Female (6–10 years) | ||||
| > 9 h | 1499 | 34 | 1 | 1 |
| 7–9 h | 2086 | 64 | 1.41(0.93–2.13) | 2.13(1.20–3.77)* |
| < 7 h | 247 | 8 | 1.46(0.68–3.16) | 1.78(0.65–4.87) |
| Young adolescents | ||||
| Male (12–15 years) | ||||
| > 9 h | 287 | 3 | 1 | 1 |
| 7–9 h | 1411 | 34 | 2.14(0.65–7.01) | 1.41(0.41–4.87) |
| < 7 h | 450 | 17 | 3.58(1.02–12.49)* | 2.19(0.56–8.51) |
| Female (11–14 years) | ||||
| > 9 h | 346 | 7 | 1 | 1 |
| 7–9 h | 1595 | 44 | 1.12(0.50–2.52) | 1.31(0.49–3.47) |
| < 7 h | 366 | 12 | 1.31(0.50–3.40) | 1.28(0.38–4.28) |
| Elder adolescents | ||||
| Male (15–17 years) | ||||
| > 9 h | 32 | 1 | 1 | 1 |
| 7–9 h | 391 | 12 | 1.42(0.18–10.98) | 0.36(0.04–3.46) |
| < 7 h | 405 | 14 | 1.87(0.24–14.40) | 0.28(0.03–2.89) |
| Female (16–17 years) | ||||
| > 9 h | 43 | 5 | 1 | 1 |
| 7–9 h | 882 | 32 | 0.50(0.19–1.29) | 0.24(0.06–0.93)* |
| < 7 h | 970 | 30 | 0.53(0.20–1.37) | 0.28(0.07–1.12) |
HRs hazard ratios, risk for overweight are displayed as HR (95%CI)
*P < 0.05 compared with ‘> 9 h’ group
aModel 1 was adjusted for age
bModel 2 was adjusted Model 1 covariates plus puberty on-set, food intake, physical activity& sedentary, domestic income and mother’s year of education